Internal-combustion engine.



A. D. DURHAM.

mrERNAL coMsusloN ENGLNE.

APPLICATION FILED FEB.V20, |9l8.

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A. D. DURHAM.

INTERNAL COMBUSTIUN ENGlNE.

APPLlcATIoN msn fsapzo. 191s.

1,297,1 18. Patend Mar. 11, 1919.

ALMOND D. DURHAM, 0F DENVER, COLOBADQ.

INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Patented Mar. 11, 1919.

Application Bled February 20, 1918. Serial No. 218,182.

T o all whom, z't may concern Bc it known that I, ALMOND D. DUnHAM, a citizen of the United States, reslding in 'the city and countyof Denverand State of Colorado, have invented certain new and useful Improvements in Internal-Combustion Engines; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this specification.

My invention relates to improvements 1n internal combustion engines, my object being to provide a construction in which the piston pressurel area is increased as compared with the dia-meter of the cylinders in which the piston is located, the cylinder being provided with an abutment between its extremities perforated to receive a tube, to the opposite extremities of which are attached bends which with the tube constitute the piston. The explosive mixture is simultaneously introduced into the cylinder on oppositeI sides of the cylinder abutment and is compreed by 'both heads of the piston, one head compressing the mixture between itself and the upper or outer extremity of the cylinder, while the other head compresses the mixture between itself and the cylinder abutment. The explosive mixture while ignited at the upper extremity of the cylinder is virtual] exploded simultaneously in contact with both heads of the piston, whereby the explosive force acts upon substantially or approximately a double surface area, thus making it practicable t0 greatly increase the power of the engine for a given diameter of the cylinder.

Any suitable means may be employed for controllin the intake and exhaust as nothin g is claimed on this mechanism. A

Having briedy outlined m improvement,

I will proceed to describe t e same in detail, reference being made to the accompanying drawing, in which is illustrated an embodiment thereof. In this drawing:

Figure 1 is a view partly in elevation and partly in central, longitudinal section cutting one of the cylinders and the correspending part of the crank case. i

Fig. 2 is a cross section taken on the line 2 2, Fig, 1, looking downwardly.

Fig. 3 is a central vertical section of the engine taken on the line 3 3, Fig. 1 looking anvar-d the left.

The same reference characters indicate the same parts in all the views.

Let the numeral 5 designate a cylinder of my improved engine, and as each cylinder is a substantial duplicate of every other cylinder, a descri tion of one will be a description of all. his cylinder is provided at its extremities with a partition or abutment 6 which, as illustrated in the drawing, is formed integral with the lower cylinder member 7, the upper cylinder member 8 being connected with the lower cylinder member by bolts 9 passing through abutting flanges 10 formed on the two cylinder members. The abutment 6 is erforated, as shown at 4, to receive a tu e 12 to one extremity of which is secured a iston head 13, as shown at 14 while to its opposite extremity is secured a piston head 15, which as shown in the drawing is formed integral with the tube. The two piston heads 13 and 15 are suitably spaced and occupy positions on op site sides of the abutment 6 of the cylin er. This is a four cycle engine. Let the numeral 16 designate a valve for controlling an intake port 17 which is in communication with a conduit 18 for supplying explosive mixture to the engine. Provision is made for mechanically opening the intake valve 16 of each cylinder at properly timed intervals to allow the entrance of a Vcharge of mix ture for each four strokes or two complete reciprocations of the piston. The valve 16 is normally held in the closed position by a spiral spring 53, a similar spring 19 being located between a shoulder 20 and a tension nut 21 threaded on the valve stem 22, the lower extremity of the stem being bifurcad, as shown at 23, to receive a gear 24 whichV is eccentrically journaled in the arms of the bifurcation, the gear being arranged to turn on a journal located beyond the center of the gear, whereby a cam action is secured for the purpose of obtaining the opening and closing movement of ,the valve 16. As this is a four cycle engine, only one opening movement of the valve should occur during each two complete reciprocations of the piston or complete rotations of the crank shaft 25. Hence, the shaft is provided with a small i the upper extremity of the -cylinder is also provided with an exhaust gear 26 whose circumference is half that of the gear 24. Consequently, the desired movement of the valve 1G is obtained, the spring 19 being under tension to maintain the gears 24 and 2G in mesh, while the b1- furcated gear-holding extremity of the valve is slotted at right angles to the bifurcation in which the gear is located to allow the valve the necessary reciprocating movement. Attention is called to the fact that no effort will be made to explain the valve motion in detail, as nothing is claimed thereon in this application. Furthermore, any suitable mechanism may be employed for controlling the intake valve.

The valve 16 opens into a passage 27 which communicates through a port 28 with cylinder. The

port 29 communicating with a passage 30 which is in communication by a port 31 with an exhaust passage 32 which may communicate with` the atmosphere through a conduit of any desired character. As shown in the drawing (see Fig. 1) the exhaust conduit which is chiefly broken away, is designated by the numeral 33, its communcation with the exhaust passage 32 being cut away on the sectioned side of the view. In this view it must be assumed that the exhaust conduit 33 is arranged in front of the cylinders and the intake conduit 18 in the rear. The exhaust valve or the valve for controlling the exhaust port 31 is designated by the numeral 34 and is provided with a stem 35 having a tension nut 36 between which and the shoulder 37 is located a spiral spring 38, a similar spring 52 normally holding the valve in the closed position, while the spring 38 maintains the gears 39 and 40 in mesh, the gear 39 being arranged between the two arms of the bifurcated extremity 41 of the valve stem, the gear being pivoted, as shown at 42, beyond its center, the bifurcation 41 being slotted to receive the crank shaft and to permit the necessary reciprocating movement of the valve stem for valve opening and closing purposes. The construction for operating the exhaust valve is substantially the same as that used for operating the intake valve, which has heretofore been described in detail. The lower head or member 15 of the piston is connected b means of a itman 43 with a crank 44 oiI the crank s aft. The upper compartment 45 of the cylinder is in communication with the atmosphere between the piston head 13 and the abutment 6 by means of perforations 46, thus preventing either compression or a vacuum condition in the cylinder between the head 13 and the abutment during the intake and compression strokes respectively. As the lower or inner extremity of the cylinder is in communication with the crank case, the comtorations 49, the tube 12 `same cylinder and pression or vacuum condition at this end of the cylinder will be negligible.

From the foregoing description the use and operation of my improved engine will be readily understood. Assuming, reforring first to F ig. 1. that the piston is moving downwardly or inwardly toward the crank case and that a charge oi' explosive mixture is being drawn into the cylinder, both in the upper compartment 45 and into the lower compartment which I will designate by the numeral 48, the said charge of mixture entering the cylinder initially through the port 28, but passing freely not only into the compartment 45 but also through the tube 12 of the piston and perforations 49 formed therein, into the compartment 48; now, as the piston begins its upward or outward stroke, the intake valve 1G will be closed and the explosive mixture will be compressed between the outer head 50 of the cylinder and the piston head 13, and also between the piston head 15 and the abutment 6 of the cylinder. Now, as soon as the piston has reached the limit of its outward stroke, the explosive mixture will be ignited initially at the outer extremity of the cylinder, but this ignition will for all practical purposes, occur in both compression compartments or between the piston head 13 and the cylinder head 50 and between the abutment G and the piston head 15. Consequently, the explosive force will act simultaneously upon both piston heads to drive the piston inwardly toward the crank case. As soon as the piston has reached its inward limit of movement and starts upon itsoutward stroke, the exhaust valve 34 will be opened and the cylinder will be scavenged of its refuse burned products of combustion, those in the compartment 45 passing directly through the exhaust port and passages while that in the compartment 48 is expelled through the perand the compartment 45. From this it will be understood that I obtain from my improved construction great power relatively, .considering the diameter of the cylinder, by reason of the fact that the piston is of such construction that nearly twice the area is exposed to the action of the explosive force as compared with other structures having the same diameter of cylinder. y Attention is called to the fact that ,this piston construction may be advantageously employed in steam engines and pumps which will be covered by simultaneously pending applications'.

Attention is called to the fact that the stems 22 and 35 for controlling the intake and exhaust valves respectively are divided so that each valve may be' quickly opened to its full extent rather than opened too gradually as might be the case if the said stems 22 and 35 were integral. As now constructed, the upper extremit of each stem acts upon a short stem mem r with which the valve piece is directly connected, the spiral springs 53 and 52 respectively serving to normally maintain the valve pieces in the closed position. This action of the upper extremity 'of the stem 22 or 35, as the case may be, occurs as the stem is approaching its upward limit of movement, thus making the openingv movement of the valve rather instantaneous than gradual. But, as heretofore stated, the invention is not limited to any specific mechanism for controlling the intake and exhaust.

ttentionis called to the Vfact that in my improved construction the intake space for explosive mixture is approximately double for the same length of piston stroke, what it is in an ordinary engine with the same size cylinder.,

The head 50 of each cylinder, as illustrated in the drawing is provided with a spark plug 51 of ordinary construction and which may be utilized in properly timing the explosions through the instrumentality of ignition mechanism (not shown).

Havin thus described my invention, what I c aim is: i

1. An engine including a cylinder closed at one end` and provided with an abutment intermediate its extremities, and a piston reciprocable therein and including spaced heads arranged on opposite sides of the cylinder abutment, the structure having a permanently open passage connecting the space between the closed end of the cylinder and one head of the piston with the space between the opposite head of the piston and the abutment of the cylinder, each of said spaces constituting a combustion chamber.

2. The combination of a cylinder having one head and an abutment, the latter Ybeing arranged between the extremities ofthe cylinder and a piston reciprooable in the cylinder and composed of two connected heads spaced'to occupy positions on opposite sides of the abutment, and a passage communieating at .one ,extremity with the space between the cylinder head and ene head of the piston and at its opposite 'extremity with the space between the opposite piston head and 'the cylinder abutment, said passage extending through the iston and its rod.

3. The combination o a cylinder having one head and an abutment, the latter being arranged between the extremities of the cyl-` inder, and a piston reciprocable in the cylinder and composed of two connected heads spaced to occupy positions on opposite sides of the abutment, a assage communicating at one extremity with the space between the cylinder head andione head of the piston and at its opposite extremity with the space between the opposite piston head and the cylinder abutment, and means for simultaneously introducing motive fluid to both of said spaces.

c 4. An internal combustion engine includmg a cylinder having a closed head, and an abutment arranged between its extremities, a plston mounted to reciprocate therein and including two spaced heads arranged on opposite sides of the cylinder abutment, said eads belng connected to move in unison, a passage having one extremity in communication with the space between one head of the piston and the closed end of the cylinder, while the other extremity of thepassage communicates with the space between the opposite head of the piston and the cylinder a utment, each of said spaces constituting a combustion chamber, and said assage extending through the piston and its rod.

5. An internal combustion engine including a cylinder having a closed head, and an abutment arranged between its extremities, a piston mounted to reciprocate therein and including two spaced heads arranged on opposite sides of the abutment, said heads bemg connected to move in unison, a paage having one extremity in communication with the space between one head of the iston and the closed end of the cylinder, w ile the other extremity of the passage communicates with the space between the opposite head of the piston and the cylinder abutment, and means for simultaneously introducing explosive mixture to both of said spaces.'

6. An intern-al combustion engine including a cylinder having a closed head, and an abutment arranged between its extremities, a piston mounted to reciprocate therein and including two spaced heads arranged on oposite sides of the abutment, said heads belng connected to move in unison, a passage having one extremity in communication with the space between one head of the piston and the closed end of the cylinder, while the other extremity of the passage communicates with the space between the opposite head of the iston and the cylinder abutment, means or simultaneously introducing explosive mixture to both of said spaces, and means for simultaneously igniting such mixture in both of said spaces.

7. The combination of a cylinder closed at one end and having an abutment approximately midway between its extremities, a piston mounted to reciprocate in the cylinder and including two connected ,spaced heads arranged on opposite sides of the abutment an forming explosion compartments respectively located between one piston head and the closed end of the cylinder and between the other piston head and the cylinder abutment, a passage connecting the explosion compartments, means for simultaneously introducing explosive mixture to both .heads arranged on opposite si compartments, and means for simultaneously igniting such mixture in both compartments.

8. The combination of a cylinder closed at one end and having an abutment located approximately midway between its extremities, a pist/0n mounte to reciprocate in the cylinder and including two connected spaced des of the abutment and forming explosion compartments between one piston head and the menne and between the the abutment, and a closed end other piston head and permanently open passage connectin the two explosion compartments, the cy mder being provided with intake and exhaust ponts controlled to open and close at properly timed intervals to operate on the four cycle principle.

In testimony of the cylinder,

whereof I ax my signature.

ALMOND D. DURHAM. 4 

